Energy, whatever its form, is the universal raw material and has become the lifeblood of modern man. Non-renewable energy sources such as oil, gas, coal or uranium are fast running out and a practical solution to efficiently and economically tap our renewable energy resources is forever pressing.
Wood burning fireplaces or stoves are well known air heating devices dating back many years. In the days of Ben Franklin stand alone wood fireplaces or stoves provided the only source of heat. Because the rate of burning of wood is not a controllable process, the local air space being heated becomes too hot for comfort or otherwise too cold. Also such heating devices had no substantial thermal capacity and were an inconvenience in that constant feeding of fuel wood was required.
Modern day fireplaces are known to be inefficient or impractical as a means for extracting heat from a combustion chamber and for evenly distributing such thermal energy into the space to be heated in spite of numerous improvements in the field. Examples of improvements in fireplaces designed to improve upon the efficiency of such auxiliary heating devices are found in U.S. Pat. Nos. 1,432,538 (W. E. DE ARMOND); 4,019,677 (A. A. DOTSCHKAL); 4,025,043 (C. W. CLEER); and 4,050,626 (T. Y. AWALT). The fireplaces and the heating systems described in these patents invariably require a main source of heat which is different from and which is added to the wood burning process. This is no doubt due to the fact that people have become used to nearly perfect temperature regulation made possible with oil or gas fired furnace and electric furnace heating systems as a result of which fireplaces are at best an auxiliary source of heat even where wood is available as a cheap combustible.
I have found that it is possible to devise a practical, efficient and economical domestic heating system which uses a wood burning fireplace as the principal source of energy with no compromise in living comfort and minimum inconvenience to the user.